Broken fingers


8 replies to this topic
  • Frostbite

Posted December 02, 2004 - 01:35 PM

#1

A little while back my clutch basket came apart. A few fingers snapped off off and I thought I could get away with a new one and an engine flush, but when I removed the clutch I found a few of the inner plates had shattered into tiny pieces. I had to completely tear the engine down to make sure I got all the metal out. I probably should have done that anyway but it would 've taken a month for new gaskets to arrive so ....
I know that you should never re-install old rings in a cylinder so I needed new rings. The piston is original and though it looks good it's got lots of miles on it so I might as well get a new piston. If I'm getting a new piston, I might as well get a big one. A big piston would have a hard time breathing with the stock cams and I already have an E pipe so....I sent my barrel to Thumper Racing in Texas to have it resleeved for their 430 kit and ordered Hotcam's intake and exhaust cams. Anybody here have experience with either?

Broken fingers

Open Sesame

  • Indy_WR450

Posted December 02, 2004 - 01:52 PM

#2

Wow Frostbite! I did not know that your snow ski front end was so hard on the clutch. :cry:
How many miles you got on that bike now? :cry:
Good choice going with the Hinson! :cry:

  • Frostbite

Posted December 02, 2004 - 01:57 PM

#3

I'd say that there's 15,000 miles on the front tire but that's like dog years to the engine since 90% of the time the rear is spinning.

  • glasseye

Posted December 02, 2004 - 02:35 PM

#4

I have the Hot Cams w/auto decompression. ('02 WR426) 1st ride, I thought the engine was missing at high RPM's but soon discovered it was hitting the rev limiter waaaay quicker. Not totally convinced the auto decompression is as good for cold starts, but after the engine is warmed, it is sure a great feature. I'll be riding this week in about 30 degrees f, coldest so far with the new cams. I'll see how the cold starting goes then.

As far as putting a sleeve in your cylinder, I've heard that is a no-no. And with your cold weather, it could be worse. No real experience, just what I've heard. Lukes Racing is boring and replating WR cylinders, no sleeve. You may want to call and get their 2-cents on the subject. I've used them on 2-strokers with great success.

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  • Frostbite

Posted December 03, 2004 - 06:26 AM

#5

With the 420 kit you may be able to bore and replate the cylinder but the walls are very thin and I don't think there'd be anything left if you bored the stock sleeve for the 95mm piston of the 430 kit. Thumper Racing presses out the old sleeve, bores the cylinder casing and then presses in a new larger nicasil plated sleeve. I've heard of some companies using unplated cast iron sleeves which I wouldn't be too crazy about, but the new plated sleeve should act like the original, only bigger.
Of course, I may be wrong.

  • SXP

Posted December 03, 2004 - 08:06 AM

#6

Frost - The Thumper Racing (TR) sleeved cylinder is NOT plated. I have one sitting here on my bench. I also have a bored out (to 95 mm) and NIKASIL plated 400 cylinder (bought from Eric Gore (EG)) which I eventually installed and currently run on my 400 (now 426 - about 2000 miles on it now). The difference in weight between the sleeved (TR) and bored/plated (EG) cylinders is huge. Make sure TR sends you the 95 mm piston with the correct size wrist pin for the 400. The first two 95 mm pistons they sent me were for the 426 connecting rod (1 mm larger diameter wrist pin). It took them three tries to get it right, but to their credit it was eventually done right. I'd definitely rebuild the crank while everything is apart. If you do, then I'd go with the 426 rod (beefier and with the larger diameter wrist pin). Of course, if you do this then make sure TR is aware of this so they send you the correct piston (confused :cry:). The 426 rod will allow you to drop in a bored out 426 cylinder and 97 mm piston for ~445 cc.

  • Frostbite

Posted December 03, 2004 - 08:38 AM

#7

Dang SXP, I was avoiding cast liners and thought theirs was plated and the cylinder's in the mail. I'm going to give them a call. Did you install cams or are you still running stock with the bore kit?
If there was anything resembling a shop here I'd get my crank done too but everytime I send a part out for work it takes 6 to 8 weeks to land back here. All this repair work is draining my 2 Trac fund. I was hoping to land one here on the first boat next summer.

  • SXP

Posted December 03, 2004 - 11:48 AM

#8

Dang SXP, I was avoiding cast liners and thought theirs was plated and the cylinder's in the mail. I'm going to give them a call. Did you install cams or are you still running stock with the bore kit?
If there was anything resembling a shop here I'd get my crank done too but everytime I send a part out for work it takes 6 to 8 weeks to land back here. All this repair work is draining my 2 Trac fund. I was hoping to land one here on the first boat next summer.



I have installed a YZ450 exhaust cam only. It's pretty tame compared to the YZ timed WR cam - smooth power, no more "hit". I've retained the decomp lever as I find it easier to start the bike cold using the old drill. Hot, however, is another story, as even a half-ass kick fires this thing up.

How was the oil filter looking? The reason I tore into my motor was 'cause I started noticing a knocking sound coincident with the appearance of an excessive amount of metal shavings in the filter. Turned out to be a failing con-rod big-end bearing.

Good luck with your rebuild.

  • Frostbite

Posted December 03, 2004 - 12:59 PM

#9

There was metal in the filter but I'm guessing that most of it is from the clutch plates. I found most of the basket pieces in big chunks but quite a bit of clutch plate material was missing. What really sucks is that I had just installed a new set of plates and springs a couple of weeks earlier. All of the plates now have chips and dings or are warped so they're not even good enough for the healing pile. :cry: The new clutch is probably why the basket came apart in the first place. Fresh clutch and new paddle tire put extra strain on the basket which may have been damaged already.
Up to that point the engine was fine with no strange noises. The only other real poblems I've had since new are a broken kickstart gear, broken throttle slide plate and broken rear shock. It's been fairly bulletproof even at these cold temperatures and I definitely don't spare it any. The only tougher bike I've had was my Honda Z-50. :cry:




 
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